Tension device and the like



l/VI/E/VTOR, Lu? Foam, er

lam/awn L PAVIA TENSION DEVICE AND THE-LIKE Flled June 23. 1926 June 7 1927.

WITNESS Wt M Patented June 7, 1927.

* UN re-n "STATES LUIGI Pavia, OE ALLnNrown PENNSYLVANIA.

TENSION Dnvicn AND THE. LIKE.

Application filed June 23,

This invention relatesto the manufacture ofeyeletedshutt-le tension levers. These are usually formed from a piece of wire by'b'ending it so as to produce a spiral. bearing portion, a shank or body portion projecting from one endof the bearing portion and formed with upstanding loops or eyelets at intervals. and an arm projecting from the other end of the spiral bearing portion and shaped for the attachment thereto of an elastic band for holding the device in proper cooperative relation with other fixed eyelets in the shuttle.

One object is to provide a tension lever of this class which may be manufactured withouta certain waste which obtains in the manufacture of such devices as at presentpracticed.

Another object is to form the said arm of the device so as to facilitatethe attachment thereto and removal therefrom of the mentioned elastic.

The drawing shows,

In Fig. 1 the improved tension lever in side elevation; and a In Fig. 2 a section on line 22, Fig. 1.

In the drawing, 1 is the spiral bearing portion, 2 generally denotes the shank or body portion projecting from one end of the body portion and formed with the up standing loops or eyelets 3, and 4 the arm projecting from the other end of the hearing portion. Except for a detail involving the arm and to be described the device follows in shape the conventional tension lever of its class, a single piece of soft iron wire being used to form it and the wire being suitably bent to produce the part 1, the part 2 with its loops or eyelets 3, and the part 4; this entails, it will be observed, a partial twisting of the metal at the bases of the eyelets.

It is very necessary and in fact substantially the invariable custom in the manufacture of these devices to temper the iron wire after the shaping thereof into its ultimate form so as to harden it and thus adapt the device to withstand the wearing action of the silk or other thread thereon Where it passes through the-eyelets, which action is otherwise found to produce nicks in the wire which cut the thread and thus render the device useless. Heretofore the practice has been to subject the device as a whole to the proper heat for tempering and then sud-o denly cool it in water. It is known that this 1926. -senai N'o. 118,112.

practice results in a considerable wasteibecause the heating and sudden cooling will in a large number of instances produce a warping of the devices resulting intlieeyeletsbeing' so badly distorted out of position that they cannot be used unless their eyelets 'are by hand subjected to a' correcting treatment, very frequently involving even individual re-posit1on1ng of the eyelets one by one if the distortion is suchthat one or more of the eyelets is out of alinement with the others. "I have sought by this invention to retain the hardening, by tempering, in the devices so as to protect them against the cutting or nicking action of the thread and at the same time to eliminate the mentioned waste incident to the production of these devices, and this I have accomplished in the followmg way: 1

I first bend the soft iron wire to the required form shown and then subject it to the tempering operation. But instead of subjecting the device as a whole to the tempering treatment I heat to a tempering heat those portions, exclusively, which undergo cutting or nicking by the thread, and then suddenly cool the wire to temper said portions, which are marked 3 In consequence of this treatment I find that when after the heating step in the tempering operation the devices are plunged in cold water to effect the hardening such hardening is not only confined to the portions 3*, where it is required, but that all of the. devices retain their original shapes, as designed, and that no distortion takes place and consequently no correcting treatment is necessary, so that an appreciable economy results in the production. In other words, the tempering treatment being isolated from those parts of the devices which are in a state of strain, especially at the twisted bases of the eyelets, and which tend to assume new positions on changes in tem erature, the devices come from the tempermg treatment without being mal-formed. As for the article itselfthere is also the advantage that if any eyelet requires at any time re-positioning as the result of accidental distortion in use this can be accomplished without breaking for the device is tractable to that end in all. portions excepting where such bending is not required and where hardness and hence brittleness is present and is requiredfor resisting wear by the thread.

The arm lin the conventional device of this class has a plain eye to receive the (rubber) elastic for yielding'ly holding the tension lever in a definite position in the shuttle and so as properly to cooperate with the other or fixed guides therein (see my Patent No. 1,439,322, for example). t is a tedious operation to attach the elastic to this eye, requiring first to thread the elastic through the eye and then knot the end of the elastic. To avoid this I provide the end of the arm 4 with an open spiral eye t. In the use of this construction the elastic is first knotted and then entered into the eye by manipulating it in a fashion to cause it to follow the spiral space existing between the convolutions of the spiraleye.

Having thus fully described my invention what I claim and desire to secure by Letters Patent is: v

A tension lever of the class described consisting of a piece of wire bent to include a bearing portion, a shank projecting from said bearing portion and having eyelets projectingthere'trom at intervals, and an arm forming one endof'the wire and bent into an eye to receive the knotted end of :1 rubber elastic and formed as an open'spiral.

In testimony whereof I aifix my signature.

LUIGI PAVIA. v 

